New Process A-230, A-250, A-390, A-745, and 2500:
If gear noise or rattle is experienced with the A-230/A-250/A-390/A-833, SAE 90 gear oil may be used in place of the ATF.
See Figure 1
The fluid level should be checked every 6 months/6,000 miles (9500 km), whichever comes first.
- Park the truck on a level surface, turn the engine OFF , apply the parking brake and block the wheels.
- Remove the filler plug from the side of the transmission case with a proper size wrench. The fluid level should be even with the bottom of the filler hole.
- If additional fluid is necessary, add it through the filler hole using a siphon pump or squeeze bottle.
- Install the filler plug; do not overtighten.
DRAIN AND REFILL
- Position the truck on a level surface.
- Place a pan of sufficient capacity under the transmission and remove the upper (fill) plug to provide a vent opening.
- Remove the lower (drain) plug and allow all of the fluid to drain from the transmission. On the A-390 top-cover three speed, remove the lower extension-to-case mounting bolt to drain the transmission.
- Reinstall the drain plug.
- Pump in sufficient lubricant to bring the level to the bottom of the filler plug opening.